Calcium oxalate monohydrate (COM) can promote the formation of urolithiasis, while calcium oxalate dihydrate (COD) is easily expelled from the body.

• 草酸钙结石的形成与尿液中草酸钙的存在形式密切相关,一水草酸钙(COM)促进尿石症形成,而二水草酸钙(COD)易随尿液排出体外。